There's a part of the eye called the "lens" which is behind the pupil. People who have bad eyes means their lens are thicker. During lazer eye surgery, the lens is shaved off abit in order to get 20/20 vision.

I suddenly remembered a show which my younger sibling used to watch and at some point in the episode they ask the main character what she learned today.

So, I'm going to ask YOU. What did you learn today?

It can be anything random, weird, irrelevant [?] and crazy just as long as it was actually something you learned.

Also how did you end up learning that?

I learned that my kids think our midnight walk around the residence means playing hide-and-go-seek. My kids consists of black and dark brown fur so and with poor vision, they are camouflaged. I now carry a flashlight and have placed bicycle light reflectors on each of their harnesses so I can see them when I direct the flashlight on them. Those sneaky bastards!